Do I need to install anything?

No. It runs in any modern browser, free, with no account required.

For Hobbyists & Makers · H-R Diagram

H-R Diagram for a galaxy rotation

Built for hobbyists & makers exploring it for fun. Play with real physics and math, no license and no setup — just open and tinker. Simulate a galaxy rotation live below — adjust the inputs and watch it respond, right in your browser.

Hertzsprung-Russell DiagramLive

the map of the stars

Controls

Presets

Your star temperature (K)

The H-R diagram plots stars by temperature and luminosity, revealing the main sequence (a diagonal band), red giants, supergiants, and white dwarfs. Your star (pink ring) sits on the main sequence where luminosity scales as T⁴.

▶ Run in Python

Data Inspector

Spectral classG

Luminosity1.00 L☉

Temperature5,778 K

Governing equation

\frac{L}{L _{⊙}} = (\frac{T}{T _{⊙}})^{4} = (\frac{5778}{5778})^{4} = 1.00

Reading this result: A cool orange K-type star: lower temperature places it low-right on the main sequence, dimmer and longer-lived than the Sun.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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More with H-R Diagram

H-R Diagram for a planet orbit H-R Diagram for a binary star H-R Diagram for a black hole H-R Diagram for a comet path H-R Diagram for a solar eclipse H-R Diagram for a supernova H-R Diagram for a star's life H-R Diagram for an exoplanet transit

Frequently asked questions

Is this good for hobbyists & makers?: Yes — this version of "H-R Diagram for a galaxy rotation" is framed for hobbyists & makers exploring it for fun. Play with real physics and math, no license and no setup — just open and tinker.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.